To arouse means to awaken or stir up a feeling, interest, or reaction in someone. When a mystery novel arouses your curiosity, it makes you eager to discover what happens next. When a teacher arouses interest in science by bringing in fascinating experiments, students become genuinely excited to learn more.

The word suggests bringing something from a quiet or dormant state into active life. A speech might arouse enthusiasm in a crowd. An unusual noise in the night might arouse suspicion. A beautiful sunset might arouse feelings of wonder and peace.

You can also arouse someone from sleep, meaning to wake them up: “The alarm clock aroused me from a deep sleep.” In this sense, it's similar to rouse.

Notice that arouse often involves emotion or awareness. When something arouses anger, fear, or excitement, it brings those feelings to life in a way that makes people sit up and pay attention. The feelings may have already been there in some small way, but whatever aroused them made them active and powerful.